# Age Structure, Growth, and Survival Rates of an Insular Population of Hemidactylus turcicus

## TL;DR

This study explores the life history of Mediterranean house geckos on the island of Bozcaada, revealing their age structure, growth, and survival in an isolated environment.

## Contribution

The study provides the first detailed demographic and morphometric baseline for an insular population of Hemidactylus turcicus in Türkiye.

## Key findings

- Males and females had maximum longevities of 7 and 6 years, with average ages of 4.26 and 3.91 years, respectively.
- Growth rates were 3.10 mm/year for males and 3.58 mm/year for females, modeled using the von Bertalanffy equation.
- The population showed subtle sexual dimorphism and stable survival rates, indicating adaptation to insular conditions.

## Abstract

The Mediterranean house gecko,
Hemidactylus turcicus
(Linnaeus, 1758), a widespread nocturnal lizard, exhibits diverse life‐history traits, yet its insular populations in Türkiye are underexplored. This study examines how Bozcaada's insular environment shapes the age structure, body size, growth rates, and sexual dimorphism of
H. turcicus
, providing a detailed demographic and morphometric baseline. We sampled 30 individuals (19 males, 11 females) from Bozcaada, Çanakkale, Türkiye, measuring snout‐vent length (SVL), body mass, and additional traits (head length, width, height, forearm, and hind leg length). Age was determined via skeletochronology, counting phalangeal Lines of Arrested Growth (LAGs). Results show a maximum longevity of 7 years for males (mean: 4.26 ± 0.33) and 6 years for females (mean: 3.91 ± 0.41). SVL averaged 45.19 ± 1.59 mm for males and 43.51 ± 2.33 mm for females, with growth rates of 3.10 ± 1.03 mm/year (males) and 3.58 ± 1.24 mm/year (females), modeled using the von Bertalanffy equation. Sexual dimorphism was subtle (SDI = 0.04, male‐biased), with no significant differences in morphometric traits between sexes. Survival rates were 0.78 for males and 0.76 for females, yielding adult life expectancies of 6.06 years (males) and 5.80 years (females), indicating a stable population. These findings suggest that Bozcaada's insular conditions, including limited resources and reduced predation, influence size, growth, and survival. This study establishes a novel profile of
H. turcicus
in an insular habitat, highlighting ecological adaptations and providing a foundation for future research and conservation strategies for this adaptable species.

This study provides a comprehensive analysis of the life history traits of the Mediterranean house gecko (
Hemidactylus turcicus
) in the insular environment of Bozcaada, Türkiye, offering novel insights into its demography, morphometry, and ecological adaptations. The Mediterranean house gecko is a widespread and adaptable species, yet its insular populations remain underexplored, particularly in Türkiye. Our study addresses this gap by examining age structure, body size, growth rates, survival rates, and sexual dimorphism in the Bozcaada population using skeletochronology and the von Bertalanffy growth model.